When specifying the logon ID for a remote virtual root, type both the domain name and the user name, separated by a backslash (\):
domain\username
If you do not give the domain name, Microsoft Index Server will not index the remote virtual roots. Note that the domain name may actually be the name of the computer, if the account is local to that computer.
User IDs associated with remote virtual-root setup must have interactive logon permission on the computer running Microsoft Index Server. For example, if /Vroot1 on index_server points to \\Computername\Share\Folder1\Folder2 and the user ID is domain\user, then domain\user must have interactive logon privilege on index_server. The simplest way to achieve this is to add domain\user to the Guests group on index_server.